Get your bio-filter going, instantly, with One & Only.
One & Only is a live nitrifying bacterial supplement best utilized when setting up a new aquarium, after a water change, cleaning your filtration, adding new fish, or after treating for diseases - One & Only will control ammonia and nitrite by converting any waste via nitrification.
To have a successful aquarium, it is key that fish waste can be converted into a non-toxic form. Establishing your bio-filter is typically done by allowing nitrifying bacteria to develop by letting your aquarium cycle, which can take weeks after setting up a new tank. During this cycle the levels of ammonia and nitrite can reach highly toxic levels that can kill fish, a process known to many hobbyists as New Tank Syndrome (NTS).
It was believed that two particular species of nitrifying bacteria were responsible for converting waste during the cycle, but through Dr. Tim`s scientific research, he showed it to not be the case. Through this research One & Only Live Nitrifying Bacteria was developed and is now used in public and professional aquariums worldwide.
Dr. Tim`s Aquatics is the merging of the twin passions of the founder: fishkeeping and science. They make setting up and maintaining an aquarium easy by sharing practical advice and proven products developed through years of experience and their own real science.
Their products are developed with a simple goal – to make fishkeeping easy. You don`t need to be a biologist or chemist - they`ve got that covered! You don`t have to make mistakes – they`ve made hundreds so you can learn from them. Just have a little patience. There`s no magic or secrets – they`ve done the research and produced the products.
Dr. Tim has published numerous peer-reviewed scientific papers on nitrifying bacteria and filtration for aquariums and aquatic life-support systems. He also has written dozens of articles and columns for aquarium trade and hobby magazines. He has been an invited speaker to many national and international conferences and regularly speaks to aquarium societies.
Dr. Tim hold numerous patents for nitrifying bacteria, their use to accelerate nitrification in aquatic systems and their detection using molecular methods.
Most orders under $39 ship for only $5.99 using a mix of economy shipping methods including UPS Ground, USPS First Class, and/or SurePost. Your order will be delivered in up to 7 business days after it ships out.
We ship 99% of the products we carry for free within the contiguous United States using a mix of economy methods including USPS First Class Mail, SurePost and UPS Ground. Your order will arrive in up to 7 business days. Just spend $39 or more!
Over 90% of shoppers receive their orders within 1-2 business days. Upgrade from free economy shipping to faster shipping for only $5.99—or spend $250 and we'll upgrade you automatically!
Expedited shipping services are available for most products if you are in a hurry. Get guaranteed delivery in 2 business days, 1 business day, or next day by 10:30 am. Costs vary by location.
Same-day shipping is available Monday-Friday for most products—place your order by 10:30 am PST. Pre-ordered and back-ordered items do not qualify, nor do drop-shipped, live, or frozen shipments.
We ship live plants, live foods, and frozen foods within the contiguous United States. Each of these categories is subject to its own $19.99 flat-rate shipping fee to cover the special packaging and/or expedited shipping costs required to ensure safe delivery. Orders with 12+ live plants ship free!
Return any new and unused item within 60 days for a full refund. Having difficulty with a product? Contact us to speak with an aquarium expert. If you need a replacement, fill out this form.
A small segment of the 180+ brands we carry require that customers contact them directly if/when problems arise. You can view the full list of those brands and get their contact info here.
We are unable to accept returns of Digital Aquatics, Neptune Systems, Vertex Aquaristik, Aqua Illumination (AI), EcoTech Marine, GHL, or Seneye products once the manufacturer's packaging seals have been broken.
Marine Depot is an authorized reseller for every product we carry. That means when you buy aquarium supplies from us, your products are not only backed by our own 60-day return policy, they also carry full factory warranties, where applicable. Some items have a 1-year warranty, others have limited lifetime warranties. Warranty coverage varies from manufacturer to manufacturer, so please read the product description of the item(s) you are considering thoroughly for details or contact us if you have warranty questions.
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